Motor vehicle



April 4, 19355.

F. CL BEST MOTOR VEHICLE Filed March 16, 1933 2 Sheets-Sheet l April 4, 1939. v I I F. c. BEST 2,153,233,

MOTOR VEHICLE Filed March. 16, 1933 2 Sheets-Sheet 2 Patented Apr. 4, 1939 UNITED STATES PATENT OFFICE MOTOR VEHICLE ton, D. C.

Application March 16,

Claims.

This invention relates to motor vehicle sus pension and steering mechanism and more particularly to motor vehicles in which the steerable road wheels of the vehicle are independently sprung. It is the principal object of the invention to provide means for supporting each steerable road wheel in such a manner that the wheels may rise and fall in a substantially vertical plane, the construction being such that the usual caster angle remains unchanged regardlessof the extent of relative vertical movement of the wheel and frame. the mechanism which serves to swing the road Wheels for steering is so designed that vertical movement of the wheel causes no such relative displacement of the component parts of the steering mechanism as'would aflect precise steering control; in other words, the construction is such that perfect steering relationship is maintained at all times It is a further object of the invention to provide independent springing for the steerable road wheels, and steering mechanism adapted to control the wheels independently, for the purpose of increasing the factor of safety.

A more specific object of the invention is the provision of independently sprung steering knuckles for the road wheels and parallelmotion devices for supporting these knuckles on the vehicle frame, whereby on relative vertical movement of either wheel and the frame the steering knuckle will be moved througha series of parallel positions.

Further objects and features of the invention will be apparent from the following description taken in connection with the accompanying drawings, in which Figure 1 is a plan view of a portion of a motor vehicle chassis illustrating one method of applying the present invention;

Figure 2 is a side elevational view corresponding to Figure 1;

Figure 3 is a view in perspective of the wheel supporting mechanism and steering apparatus a associated with one of the steerable road wheels;

Figure 4 is a fragmentary sectional view illustrating a supporting element; and I Figure 5 is a diagrammatic view in plan of the structure shown in Figure 3.

The preferred embodiment of the invention illustrated in the drawings is described herein in detail in order to facilitate an understanding of the principles of the invention. It will neverthe- 5 less be appreciated that no limitation is intended It is a feature of the invention that 1933, Serial No. 661,12

by the use of specific language and that such alterations andfurther modifications are contemplated as fall within the scope of the invention.

Referring to the drawings, it will be observed that the vehicle frame is shown as comprising the side frame members Ill and cross frame members l2, the latter serving to connect the side frame members rigidly together and also serving as a support for a plate 13, the latter being secured to the cross frame members in any convenient manner, for instance by riveting, and also being preferably secured to the side frame members as indicated at l5. This plate may be conveniently used as a support for several elements of the wheel suspension and steering mechanism as hereinafter described.

In describing the wheel suspension it will be convenient to refer flrst'to the arrangement at the left hand side ofthe vehicle, the suspension for both steerable road wheels being preferably similar and the same reference characters being employed where the parts are identical.

A pair of links l5 and H, which may be referred to as radius arms, are pivotally connected to the vehicle frame for movement about parallel and substantially horizontal axes.- For in- "stance, a supporting bracket I 8 may be riveted or otherwise secured to the side frame member ID as indicated at i9, this bracket having a laterally extending portion provided with integrally formed upper and lower forked portions 2| and 22 in which the radius arms I! and I6 respec-. tively are received, bolts 23 extending through these forked portions and through the radius arms serving as a fulcrum for the latter.

At their outer ends the radius arms may be similarly provided with a pivotal connection to a steering knuckle supporting member 25, the latter being provided with forked portions 26 and 21 to receive the radius arms, bolts 28 being employed to provide the necessary fulcrum. The'axes of the bolts 28 are substantially parallel to the axes of the bolts 23 and it is quite clear that the knuckle supporting member 25 may be moved in a substantially vertical plane and will pass through a plurality of parallel positions; in other words, the, knuckle supporting member 25 is supported by a parallel motion device so that its angular position with respect to the vehicle frame remains unchanged regardless of the extent of vertical movement of which it partakes.

The radium arms l8 and I! are in effect parallel and are so shown in the drawings, although it is quite obvious that they need not be of the same configuration or strictly parallel throughout their length, it being intended. however, to employ the term "parallel links, to cover any pair of links in which the pivotal extremities are arranged substantially as shown in the drawings. Thus when theselinks are described as being of equal length, which is preferably the case, it is understood that the lengths of the links as measuser between the pivotal extremities thereof are equal.

In order to relieve the lateral strain on the pivotal connections between the radius arms It and i1 and the vehicle frame, additional links 30 and II are preferably provided, these links being referred to for convenience as radius rods,

Each of the radius rods is rigidly connected with a respective radius arm, for instance the arms i8 and Il may beformed to provide laterally projecting sockets 32 in which the outer ends of the radius rods are received and secured. The inner ends of the radius rods 30 and ii are pivotally connected to the frame, the pivotal axis of the radius rod 30 coinciding with the axis of pivotalconnection of the radius arm It to the frame and the pivotal axis of the radius arm 8| coinciding with the pivotal axis of the radius arm ll.

The plate It preferably comprises the support for the radius rods 30 and 3|, a bracket 33 being secured to the underside of the plate and depending to aflord bearings in which the bosses 34 formed on the inner ends of the radius rods are pivotally supported in the conventional manner. It will be observed that in eflect the radius- -rods 30 and 3| are of a length which is meassured between the axes of the bolts 28 and the axes of the bosses 34 and that these rods function in the same manner as the radius arms i6 and I! in supporting the member 25 for movement in a substantially vertical plane. With reference to the efiective length of the radius rods and the radius arms, it will be appreciated that this must be measured by the length of a perpendicular. line from the axes of the bolts 28 to the corresponding axes of the pivotal points of connection of the radius rods and radius arms to the frame. Thus in speaking of the. effective length of these members it is intended that the term shall apply to the radius of the are through which the knuckle supporting member 15 is swung with respect to the frame.

The steering knuckle supporting member 2i is provided adjacent its upper end with a laterally extending. portion 36 on which the steering knuckle 31 is pivotally mounted for swinging movement in a substantially horizontal plane for vehicle steering purposes. This pivotal connection may assume various form, for instance the usual king pin 38 passing through the supporting membe 2| andthe steering knuckle 81 may be provided to serve as a fulcrum for the latter, it being understood that the pin 38 may be inclined to the vertical to provide .the usual 1088178! eil'ect. Formed integrally with bi rigidly secured to the knuckle is a disk 40 to which the usual brake backing plate, not shofii, may be secured, a wheel spindle 42 projecting from the face of the disk 4| and ail'ording a support for the road wheel which is rotatably mounted therejcd 'ln the conventional manner.

e. lower portion. of the knuckle is provided witha steering arm 4| 'a-Divotal connection as indicated-at withasteering rod 44, and elf-bell crank lever 46 is provided with an arm 41 having a pivotal connection as indicated atuwiththeopnmiteendofthesteeringrod amass:

44. The bell crank lever is provided with a bearing boss 49 by which it may be pivotally mounted on a bracket 50 secured to the underside of the plate I! and depending therefrom, the lever 46 behilg oscillatable in a substantiallyhorizontal pla c.

It is importantto note that if the efiective length of the steering rod- 44 as measured by the perpendicular distance between lines parallel to the pivotal axes of the wheel supporting arms and passing through the points 43 and 48 of pivotal connection of the rod to the steering arm 45 and the bell crank lever 46 respectively 4 vertical plane since the radius rod is in" eifect a part of the system of parallelograms which is employed to support thesteering knuckle. Thus perfect steering is secured and there is no tendency for the wheels to partake of swinging steering movement or for the parts of the steering mechanism to bind as the road wheel moves up and down in passing over an irregular; road bed,

it being commonly recognized that steeringperfection is obtained only approximately with conventional steering mechanism and spring sus pension.

The bell crank lever 4' is provided with lever arm 58 which is pivotally connected as at "to a drag link the latter being in turn connected in conventional manner with gearing within the housing 58, the latter being located at the lower end of the steering column It and carrying at its upper end the usual steering hand wheel for manipulating the gearing and associated linkage.

The construction at the right hand side of the vehicle is identical with that at the left hand'side with the exception that the right hand radius rods 30 and 3!, of which the latter is shown in Figure l of the drawings, are displaced forwardly of the radius rods employed in connection with the road wheel at the left side of the vehicle. It will be observed, however, that since the axes of swinging movement of the arms I! intersect at the center line of the vehicle and the axes of each link i1 and the associated rod II are coincident, the effective lengths of the parallel links supporting the two road wheels are equal. It is important to note that if the steering connections for one wheel including the steering rod 44 are broken, the vehicle can still be steered by reason of the independent associated with the op posite road wheel.

The vertical movementof the road wheels on meeting obstructions may be resisted by means of one or more transversely extending leaf spring assemblies II, two of these assemblies being shown in the drawings. These springs are secured intermediatetheir ends to the plate II, for instance by bolts 83 and are provided adjacent their op-. posite outerends with'shackles l4 which are in themtoilexinasubstantisllyverticslplane-and 1| amazes porting links 'andthe steering mechanism is illustrated, aconsiderable portion of the frame and other details being omitted. It will be observed that the axis about which each link I1 rises and falls with the road wheel is indicated at A-A, and the efiective length of each of these links is represented at a. The efiective length of each of the steering links 44, indicated at b is the same as that of the links 17.

It will be observed that in the preferred form of the invention illustrated in the drawings, the axes of pivotal connection of the links to the frame and the wheel are inclined with respect to a vertical plane containing the longitudinal axis of the vehicle. While this arrangement of the axes is not essential, it facilitates the application of steering mechanism to the wheels, and furthermore, since the axes are inclined in such manner as to converge toward the front end ofthe vehicle, the wheels may yield to some extent on meeting an obstruction. Thus when an obstruction is encountered by either wheel, it not only rises, but moves rearwardly to a slight extent and is thus enabled to more readily surmount th obstruction and pass over it. 4

It will also be observed that since each of the links lfiand IT is pivoted to the frame and to the wheel at points relatively displaced longitudinally .of the vehicle, the rearward thrust on the wheels is transferred more directly by these links to the frame, being applied nearly perpendicularly at the axes of the bearings, the inclination of these axes with respecinto the longitudinal axis of the vehicle being of assistance in obtaining the desired result.

The construction is characterized by extremely low unsprung weight which adds to easy riding M qualities and increases the life ofthe tires and their adhesion to the road. The invention furof the springs is not affected, there being no tendency to wind the springs up in response to braking torque and thus fore and aft movement of the vehicle on application of the brakes is substantially eliminated.

It will also be noted that the spring resistance is carried to a point adjacent the loading plane of the wheel with the result that side sway ordinarily developed when the vehicle is turned sharply at high speed is materially reduced.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent isz I 1. In a motor vehicle, the combination with a vehicle frame, of a steerable road wheel, a steering knuckle carrying said road wheel, a steering knuckle supporting member, and a pair of parallel links associated with said frame and said member to permit vertical movement of the latter, each linkhaving a pivotal connection with said memher and pivotal connections with said frame parallel to said first named pivotal connection at knuckle may move into different parallel positions with respect to said frame, and yielding means for resisting such movement, said frame comprising side frame members, and a cross frame member connecting said side frame members and comprising a support for said links and said yielding means at points spaced from and intermediate said side frame members.

I 2. In a motor vehicle, the combination with a vehicle frame, of a pair of road wheels disposed adjacent one end of the frame at opposite sides thereof, and means supporting each of said wheels on said frame 'for rising and falling movement with respect to said frame independently of the other wheel, said means comprising a pair of generally laterally extending wheel supporting links, the links of each pair being pivotally connected with the associated wheel and being pivotally mounted ,at their inner ends on said frame for swinging movement about separate parallel axes, the point of pivotal connection of at least one link of each pair with the frame being displaced, longitudinally of the vehicle with respect to the point of pivotal connection with the frame of the corresponding link of the other pair, the axes of one of the links of each pair being disposed above the, axes of the other link of the pair,

said axes being inclined at an acute angle with respect to the vertical plane containing the longitudinal axis of the vehicle.

3. In a motorvehicle, the combination with a vehicle frame, of steerable road wheels disposed adjacent one end of the frame at opposite sides thereof, and means supporting each,

of said wheels on said frame for rising and jailing movement with respect to said frame independently of the other wheel, said means comprising laterally extending upper and lower wheel supporting links associated with each wheel and pivotaily connected with said wheels and with said frame and extending across the longitudinal center line of the vehicle, the corresponding upper and lower links associated with the opposite wheels lying in a common substantially hori-- zontal plane and being relatively displaced longitudinally of the frame.

4.v In a motor vehicle, the combination with a vehicle frame, of a steerable road wheel, a steering knuckle carrying said road wheel, a steering knuckle supporting member, and a pair of parallel links associated with said frame and said member to permit vertical movement of the latter, each link having a pivotal connection with said member and pivotal connections with said 1 frame parallel to said first named pivotalconnection, whereby said knuckle-may move into different parallel positions with respect to said frame, and yielding means for resisting such movement, said frame comprising side frame members, and a cross frame member connecting said side frame members and comprising a support for said links and said yielding means at points spaced from and intermediate said side frame members. 4

5. In a vehicle, a frame embodying a pair of side members and a front cross member, a pair of front wheels, spring. means for connecting said wheels to said frame, and, on either side of the vehicle, two respective links means, each embodying a substantially V-shaped lower link whose limbs are respectively pivoted at a first point situated on said cross member and at a second point situated on the corresponding side member, at a greater distance from thelongitudinal axis of the vehicle'than said first point, the pivotal nected at one end to one of said axles, bearing members arranged atthe other ends of said distance members, and bearing members arranged at the ends of said axles for pivotally connecting said axles to said frame for oscillation about axes arranged a't an angle with respect to the longitudinal axis of said frame, each axle, having the bearing member at one end thereof and the 20 hearing memberat one end of the distance member connected thereto arranged on opposite sides of the central longitudinal axis of said frame.

7. vIn a suspension for a steerable ground wheel of a motor vehicle having a frame structure, means for mounting said frame structure on said wheel for vertical displacement of said wheel independently of the remaining ground wheels of a the vehicle and including a spindle rotatably Journalling said wheel, a king pin providing a steering swivel for said wheel, said mounting means further including a substantially V-shaped link adapted to guide vertical displacement of said king pin, the arms of said link having,

axially aligned pivotal bearings, and means for pivotally supporting said link arm bearings for swinging movement of said link about an axis inclined with respect to the longitudinal and transverse vertical midplanes of the vehicle, saidlink arm bearings being located on opposite sides of said longitudinal vertical mid-plane.

B. In a motor vehicle, the combination with a vehicle frame structure, of a pair of steerable road wheels disposed at opposite sides of and adiacent the forward end of said frame strucs,ias,sss

ture,means alsociatedwitheachof said wheels I and said frame structure for supportingand iding said wheels for independent rising and falling movement, each of said wheel supporting and guiding means including at least one link having arms diverging from a wheel for pivotal connection to said frame structure, means providing a pivotal connection between the ends of said diverging arms of each of said links and said frame structure whereby each of said links swings about an axis inclined at an acute angle with respect to the longitudinalvertical midplane of the vehicle, the diverging ends of the arms of one of said links lying on opposite sides ofa vertical plane containing said axis of the other of said links, steering knuckles for said wheels,tle rod means articulated to saidknuckles, and steering motion imparting means operably connected to said tie rod means and positioned in the spaces provided by the diverging arms of said links. a

9. A unitary wheel supporting link and torque arm structure for vehicle suspensions of the independent type, generally L-shaped in plan, hav-- ing pivot bearing means atthe extremities of the legs for association with a vehicle frame, and a pivot bearing means adjacent the juncture of the legs.

10. In a motorz vehicle, the combination with a vehicle frame, of a steerable road wheel, a steering knuckle carrying said road wheel, a steering knuckle supporting member, and a link associated with said frame and said member to support the .latter for vertical movement with respect to the frame, 'said link being pivotally connected with said member and having divergent arms plvotally connected to said frame at spaced points, one of said arms extending geherallydongitudinally of thevehicle frame and being deflected inwardly from a straight line connecting said spacedpoints, whereby said road wheel may move through a greater are in steering without engaging such longitudinal arm.

FRANK C. BEST. 

